A 64 y.o. farmer was bending over in the hay barn when a bale of hay weighing 150 lbs landed on his back.
He became instantly paraplegic. He has a spinal nerve stimulator because of chronic lumbar pain.
He has no bony injury and cannot get an MRI. What needs to be done?
Our patient had SPINAL SHOCK. This refers to loss of spinal cord function caudal to the level of injury with flaccid paralysis, anesthesia , loss of reflexes and bowel or bladder dysfunction. It is NOT defined as hypotension. There is acute hypotension in some cervical and high thoracic spinal injuries which is the result of impaired autonomic control. When the autonomic nervous system isn’t receiving signals from the brain to increase the tone of blood vessels they remain dilated and hypotension results. Our patient had spinal shock with a normal blood pressure because his injury was distal enough to allow for autonomic control of blood pressure.
spinal cord tracts
Spinal cord assessment-THE EXAM
Babinski- The Babinski reflex is often the first indication of spinal cord injury after trauma. It is usually present in cervical myelopathy as well, a more chronic process.
Hyperreflexia/ Clonus- In acute spinal cord injury areflexia is present. Clonus may develop months later after acute spinal injury . In cervical myelopathy signs of upper motor neuron pathology include : hyperreflexia, Hoffmann’s reflex and clonus.
Incontinence or urinary retention- Either retention or incontinence can occur after spinal injury. Usually injuries above T12 cause detrusor dyssynergy and retention occurs. Injuries below T 12 cause loss of muscle tone in the bladder and sphincter leading to incontinence.
Hoffmann’s sign is suggestive of corticospinal tract dysfunction localized to the cervical cord. If you flick the tip of the middle finger, the thumb and index finger move togerher.
While many injuries to the cord; gunshot wounds and fractures causing cord transection are irreversible there are also many injuries which reverse in 24-72 hours.
spinal cord concussion is a transient paraplegia or neurapraxia with varying degrees of motor weakness that resolve in 24-72 hours. These injuries occur in a variety of contact sports including football, hockey MVCs and falls. While in adults spinal stenosis can cause contusion of the cord with flexion or extension injuries, in children hypermobility can allow the cord to contact bony elements causing neurologic findings. Often, especially in children. imaging is not fruitful and the injury is thought to be due to axonal stretching.
Spinal cord compression-While it is most common to have a cervical or lumbar disc herniation with neurologic findings, thoracic disc herniations are also known to cause neurologic findings including Brown-Sequard syndrome and paralysis. Herniated thoracic discs can cause paraplegia in two ways; direct compression of the cord through central herniation or lateral herniation at the level of T8,9 involving the artery of Adamkiewicz and causing spasm or occlusion of the artery with an anterior spinal cord syndrome. The anterior cord syndrome presents with motor paralysis below the level of the lesion due to injury to the corticospinal tract, retained proprioception and vibratory sensation due to intact dorsal columns, and areflexia.
an acutely herniated disc can cause spasm or occlude the artery of Adamkiewicz causing paralysis
An astute ED resident performed a thorough neurologic evaluation and when he attempted to elicit clonus the patient complained of severe pain. This was an indication that the cord lesion was incomplete and While the corticospinal tract was affected, the lateral spinothalamic tract was not. He lacked proprioception as well, which is usually preserved in the anterior spinal artery syndrome.
This made occlusion or spasm of the anterior spinal artery unlikely. while our patient could not get an MRI because of his stimulator and was awaiting a myelogram, his ct was re-read noting a herniated disc at T8 with severe canal stenosis. He was taken to the OR.
Our patient underwent a decompression at T8-T10 for a herniated disc and removal of the spinal cord stimulator. By the next day he had 5/5 strength in his legs and was walking. The probable mechanism for his early recovery is an acutely herniated disc causing a cord concussion.
Chikuda H, Seichi A, Takeshita K, et al. Correlation between pyramidal signs and the severity of cervical myelopathy. Eur Spine J. 2010 Oct;19(10):1684-1689. Ramakonar H, Fehlings M. Time is spine:new evidence supports decompression within 24 h for acute spinal cord injury. Spinal Cord 2021;59(8):933-934.
Fischer I, Haas C, Ranghupathi R, Jin Y. spinal cord concussion: studying the potential risks of repetitive injury. Neural Regen Res 2016 Jan;11(1):58-60/
Guest J, Griesdale D, Marotta T. Thoracic disc herniation presenting with transient anterior apinal artery syndrome. Interv Neuroradiol 2000 Dec;6(4):327-331.